Geopolymer-based moisture and chloride sensors for nuclear concrete structures

Student thesis: Doctoral Thesis

Abstract

The reinforced concrete structures that support transport, energy and urban networks in developed countries are over half a century old, and are facing widespread deterioration. The main cause of degradation — reinforcement corrosion, accelerated by moisture and chloride exposure — costs the global economy a staggering $2.3 trillion per year (3.4% GDP, 2013). The nuclear industry faces a particular challenge, as concrete assets are usually coastal and can underpin safety-critical structures and radiation barriers. Passively-cooled waste stores, for example, are often ventilated with unfiltered sea air.To deliver structural health monitoring and maintenance strategies, industry requires both moisture/chloride sensors and concrete repair materials. To date, monitoring and maintenance have been viewed as separate challenges. The work in this thesis demonstrates that geopolymer binders — a class of adhesive concrete repair materials — can be electrically interrogated and used to monitor moisture and chloride concentrations on concrete surfaces, or as stand-alone sensors. This can be achieved without sacrificing the ability of the geopolymer to form an effective repair.This thesis outlines first-time demonstrations of moisture and chloride sensors based on fly ash geopolymers, and the fabrication of additive-free, ambient-cured, non-structural geopolymer repairs. In achieving these aims, the work demonstrates that affordable, combined monitoring and maintenance technologies for concrete can be delivered. Reducing the number of steps in deploying repairs and sensors will allow more of our ageing concrete infrastructure to be updated and repaired, so that it can meet modern expectations of safety, and remain resilient in the face of climate change.
Date of Award29 Jun 2020
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SponsorsUniversity of Strathclyde
SupervisorMarcus Perry (Supervisor) & Andrea Hamilton (Supervisor)

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